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As the father of a 13-year-old, Justin Hartley has more parenting experience under his belt than some of his "This Is Us" co-stars. But that doesn't mean he's giving pointers to Mandy Moore and Milo Ventimiglia, who play his mom and dad on the NBC drama.

“When you watch them, it’s hard to believe that they’re not parents," Hartley told Head of TODAY Parents Rebecca Dube at a breakfast screening of “This Is Us” hosted by the TODAY Parenting Team Tuesday. "I’m a firm believer in staying out of the way. When you’re on a team and the guy’s throwing a no-hitter, you don’t talk to them. You let them do their thing. Mandy and Milo have a special thing going on. There’s also a skill involved in doing it on TV versus what really happens.”

Justin Hartley, who stars as Kevin on NBC's "This Is Us," speaks with Rebecca Dube, the head of TODAY Parents, at a TODAY Parenting Team breakfast in New York.Tyler Essary / NBC

In fact, Ventimiglia's moving portrayal of patriarch Jack Pearson resonates with Hartley — especially the scenes between Jack and Kate (Chrissy Metz), which remind him of his relationship with his own daughter, Isabella.

"As a grown man, I’m constantly trying to arm her with everything I possibly can so that all of her life is streamlined," Hartley said. "I'm going to give her all of the information and all of the tools. And then there are times when I have to ask for her forgiveness because I messed up. And it’s heartbreaking. You mess up as a dad, and you have your worst moments."

Isabella watches "This Is Us" herself — her friends (and their parents) are fans too. And fortunately, she's not too weirded out that her dad is considered a heartthrob by ... anyone who's seen the charming actor.

"She’s proud of the show and I think she thinks it's pretty cool that her dad is on a show that everyone’s watching, especially at that age," Hartley said. "I’m doing something that her friends can watch without feeling weird about it. But the heartthrob status? She’s really smart, so she’s like 'Oh, I guess it goes with the territory.’ I don’t think she gets it. I’m no Zac Efron. And I know that, because she’s told me. There are some boys in her school that I can’t hold a candle to. But I think she understands that it goes with the territory."

Having a teen keeps you grounded — even if you're a TV star.

"Every week, she’ll come home and tell me these things that are cool now," he said. "And I’m like, 'OK, great, I got it.' So, I have this arsenal of things that are cool that we can use. And then four days later, I pull it out and she’s like ‘We don’t …’ And I’m like ‘I know, I was just making sure that you’re still cool.’ And then you realize how just uncool you are. But also realizing you’re uncool kind of makes you cool doesn’t it? It centers you. You’re like ‘I don’t need all that.’ And plus, they don’t know what the hell they’re talking about.”

"I started to realize that it really does resonate with 10-year-olds, 13-year-olds, 15-year-olds, 20-year-olds, 60-year-olds, 80-year-olds, men, women, poor, rich, black, white — doesn’t matter," Hartley said. "I find myself relating to Beth (Susan Kelechi Watson), and Beth is a woman. I’m like, ‘Yes! I’m just like that!’ The thing about these characters is that even if it's something that may be totally opposite of what you are, you find yourself relating to these human beings.”

Tyler Essary / NBC

He added that he loves that "This Is Us" has become a weekly bonding ritual for families.

“I have people coming up to me and telling me, ‘I have a daughter who's into this, I have a son who’s into this, and they hate each other. My wife works, I work, we never see each other. I love her, but she’s a stranger. And now we have a time when we come together and all watch this and all love it, so we have our family time.’ It’s bringing that family closer together. So that's beyond anything I ever thought I’d do with my life — be a part of something like that.”

Full disclosure: "This Is Us" airs on NBC, which is owned by the same parent company as NBC News and the TODAY Show.